English language Suomen kieli Russian language

Apatite deposit formation

It is hard to give answer to the second question about apatite deposit formation in the Khibiny and reasons why there is no apatite in other regions. There are several assumptions; the reasonable one is magmatic origin of apatite ore deposits. Based on this hypothesis, melted magma coming from the deep magmatic source by fractures-faults moved to upper of the Earth crust. It was rich in sodium, potassium, aluminum, silica and dissolved vapors of water, fluorine, phosphate. Filling the fault cavity, magmatic melt cooled down and transformed into crystalline rock. Each new portion of melt by composition, i.e. main chemical elements content was different from previous one. One of such portions resulted in separation of phosphate, fluorine, potassium and formation of the new rich apatite deposits.

Central mine

Successful exploration of the new apatite deposits can be done only within the large rockmass of nepheline ores similar to the Khibiny. But such massifs were not found somewhere else. The Khibiny were and still are unique storehouse of mineral fertilizers.

The most challenging in the ore formation are the issues of ore matter origin and way of its deposition in ore-hosting structure. Deposits of sulfide copper-nickel ores of the Khibiny massif are associated to basic ores-gabbro and norites. They like a mushroom with curved-up cap and thin stipe which serves as ore conduit. Metals like copper, nickel, cobalt as compounds with sulfur, i.e. sulfides comes by stipe into mushroom body together with magmatic melt but they don’t dissolve, on the contrary, differentiate into bunches. In comparison, try to put several drops of oil into glass of water. Would you mix it up, oil will never dissolve in the water and fat spots will float on the surface. It is the same to sulfide bunches, they do not form the homogeneous melt together with magma.

However, unlike light oil drops, bunches due to higher density are sinking into the lower part of the mushroom’s cap where they form bottom deposits of copper-nickel ores.

Typical example of sedimentary deposits is sand-gravel deposits and common clay. You already know how it was formed during glacier melting. Pile of stones and sand were heated under the sun and ice was melted near it faster. Here occurred lakes. In some places the ice cracked and such fissures together with melted water came to stone material. After the glacier melted completely, former lakes became moraine hills and a large ridges consisting entirely of washed sand-gravel material with clay lenses were formed along the fractures.

Based on the most well-known deposits of different minerals in the Kola area as illustration we tried to restore a simple picture of its origin and formation. Natural processes of ore formation are really complicated and we don't know all historical details of geology. We should remember that each mineral is a rock that has its own useful properties. This means that deposit occurrence is a result of geological development of the Earth crust at a specific locality. If consider the duration of ore formation processes in comparison to human civilization existence, it should be stated that mineral resources are non-renewable.

Индекс цитирования     Яндекс.Метрика